Constant in Golang

Go supports constants of character, string, boolean, and numeric values. And you can not change value of constant.

const declares a constant value

A const statement can appear anywhere a var statement can.

With left sample code, it will make error at n = 1, because you can change value of n

Now, please remove line

n = 1

and it run

package main
import "fmt"

const s string = "constant"
func main() {
    fmt.Println(s)
    const n = 500000000
    fmt.Println("constant n = ", n)
    n = 1
}

package main

import "fmt"

const s string = "constant"

func main() {
	fmt.Println(s)
	const n = 500000000
	fmt.Println("constant n = ", n)
	//n = 1
}